X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=lex.icl;h=6966cde7acf7095d0627c7e18108c5818f87fc02;hb=e82c306fc0f6401a09d3d180e20070664935a390;hp=d46aaa8a3a61265ffccdcee98c2b2182c11c1be5;hpb=6910d87166dedb7032fd31684e52df3d0b25910e;p=cc1516.git diff --git a/lex.icl b/lex.icl index d46aaa8..6966cde 100644 --- a/lex.icl +++ b/lex.icl @@ -1,151 +1,69 @@ implementation module lex +import Control.Monad import Data.Either -import Data.List -import StdString -import System.CommandLine -import StdFile -import StdMisc -from StdFunc import id, const import Data.Maybe -import Control.Applicative -import Control.Monad -import Control.Monad.State -from Data.Func import $ - -// Misschien moeten we hier continuation style van maken -instance toString lexerOutput where - toString l = "dit is een lexer output, danwel error\n" - -lexer :: [Char] -> LexerOutput [Token] -lexer _ = Left "Not Implemented" - -//lexer functions -identT = alpha >>= \a -> many (char '_' <|> alphaNum) >>= \as -> return $ IdentToken [a:as] -numberT = optional (char '-') >>= \sign -> (some digit) >>= \n -> case sign of - Nothing -> return $ NumberToken $ 5 //fromString n - _ -> return $ NumberToken $ -5 //(fromString n) * -1 -charLT = liftM CharToken item -char2T = item >>= \c1 -> case c1 of - ':' = char ':' >>| return DoubleColonToken - '<' = char '=' >>| return LesserEqToken - '>' = char '=' >>| return GreaterEqToken - '=' = char '=' >>| return EqualsToken - '&' = char '&' >>| return AmpersandsToken - '|' = char '|' >>| return PipesToken - '-' = char '>' >>| return ArrowToken -char1T = item >>= \c1 -> findT c1 charTokenMap -varT = string (fromString "var") >>| return VarToken -voidT = string (fromString "Void") >>| return VoidToken -returnT = string (fromString "return") >>| return ReturnToken -ifT = string (fromString "if") >>| return IfToken -elseT = string (fromString "else") >>| return ElseToken -whileT = string (fromString "while") >>| return WhileToken -trueT = string (fromString "True") >>| return TrueToken -falseT = string (fromString "False") >>| return FalseToken - -Start :: *World -> *World -Start w -# (args, w) = getCommandLine w // We lezen nu nog standaard van stdin -# (out, w) = stdio w -# (toparse, out) = readEntireFile out -# out = out <<< toString (lexer toparse) -# (b, w) = fclose out w -| not b = setReturnCode 1 w -= w - where - readEntireFile :: *File -> *([Char], *File) - readEntireFile f - # (b, c, f) = freadc f - | not b = ([], f) - # (cs, f) = readEntireFile f - = ([c:cs], f) - - - -charTokenMap = [('(', BraceOpenToken) - ,(')', BraceCloseToken) - ,('{', CBraceOpenToken) - ,('}', CBraceCloseToken) - ,('[', SquareOpenToken) - ,(']', SquareCloseToken) - ,(',', CommaToken) - ,(':', ColonToken) - ,(';', SColonToken) - ,('.', DotToken) - ,('+', PlusToken) - ,('-', DashToken) - ,('*', StarToken) - ,('/', SlashToken) - ,('%', PercentToken) - ,('=', AssignmentToken) - ,('<', LesserToken) - ,('>', BiggerToken) - ,('!', ExclamationToken)] -findT c [] = fail "Unrecognized character" -findT c [(k,v):xs] = if (c==k) (return v) (findT c xs) - - -// Clean adaption of Yard, a parsec like parser combinator -:: Parser a = Parser ([Char] -> (LexerOutput a, [Char])) - -runParser :: (Parser a) [Char] -> (LexerOutput a, [Char]) -runParser (Parser p) s = p s - -instance Functor Parser where - fmap f s = liftM f s - -instance Applicative Parser where - pure a = Parser $ \s -> (Right a, s) - (<*>) sf s = ap sf s - -instance Monad Parser where - bind p f = Parser $ \s -> let (out, rest) = runParser p s in case out of - Left e = (Left e, rest) - Right t = runParser (f t) rest - -//gives us some, many and optional -instance Alternative Parser where - empty = zero - (<|>) p1 p2 = Parser $ \s -> let (out, rest) = runParser p1 s in case out of - Left e = runParser p2 s - Right t = (Right t, rest) - -//parser that fails with error -fail :: String -> Parser a -fail e = Parser $ \s -> (Left e, s) - -//parser that always fails -zero :: Parser a -zero = fail "Zero parser" - -//matches exactly one Char -item :: Parser Char -item = Parser $ \s -> case s of - [] = (Left "Unexpected empty input", s) - [x:xs] = (Right x, xs) - -//matches any char which satisfies f -satisfy :: (Char -> Bool) -> Parser Char -satisfy f = item >>= (\r -> if (f r) (return r) zero) - -//tries a parser, if it fails returns a default value -optionalDef :: a (Parser a) -> Parser a -optionalDef def p = p <|> return def - -//matched given char -char :: Char -> Parser Char -char c = satisfy (\i -> c==i) //I hate that we can't do: satisfy (==c) - -alpha :: Parser Char -alpha = satisfy isAlpha - -digit :: Parser Char -digit = satisfy isDigit - -alphaNum :: Parser Char -alphaNum = alpha <|> digit - -//matches a given String -string :: [Char] -> Parser [Char] -string s = mapM_ char s >>| return s \ No newline at end of file +import Data.Map +import StdString +import StdBool +import StdList +import StdChar +import qualified Text + +SingleCharTokens :: Map Char Token +SingleCharTokens = fromList [ + ('(', BraceOpenToken), (')', BraceCloseToken), ('{', CBraceOpenToken), + ('}', CBraceCloseToken), ('[', SquareOpenToken), (']', SquareCloseToken), + (',', CommaToken), (':', ColonToken), (';', SColonToken), + ('.', DotToken), ('+', PlusToken), ('-', DashToken), ('*', StarToken), + ('/', SlashToken), ('%', PercentToken), ('=', AssignmentToken), + ('<', LesserToken), ('>', BiggerToken), ('!', ExclamationToken)] + +EscapeMap :: Map Char Char +EscapeMap = fromList [ + ('a', toChar 7), ('b', '\b'), ('f', '\f'), ('n', '\n'), ('r', '\r'), + ('t', '\t'), ('v', '\v')] + +lexer :: [Char] -> LexerOutput +lexer [] = Right [] +lexer x = case lex x of + (Right t, rest) = lexer rest >>= \ts.Right [t:ts] + (Left e, _) = Left e + +lex :: [Char] -> (Either String Token, [Char]) +lex [] = (Right EndOfFileToken, []) +lex ['/':'/':x:rest] = if (x == '\n') (lex rest) (lex ['/':'/':rest]) +lex ['/':'*':x1:x2:rest] = if (x1 == '*' && x2 == '/') + (lex rest) (lex ['/':'*':rest]) +lex ['v':'a':'r':rest] = (Right VarToken, rest) +lex ['V':'o':'i':'d':rest] = (Right VoidToken, rest) +lex ['r':'e':'t':'u':'r':'n':rest] = (Right ReturnToken, rest) +lex ['i':'f':rest] = (Right IfToken, rest) +lex ['e':'l':'s':'e':rest] = (Right ElseToken, rest) +lex ['w':'h':'i':'l':'e':rest] = (Right WhileToken, rest) +lex ['T':'r':'u':'e':rest] = (Right TrueToken, rest) +lex ['F':'a':'l':'s':'e':rest] = (Right FalseToken, rest) +lex ['I':'n':'t':rest] = (Right IntTypeToken, rest) +lex ['C':'h':'a':'r':rest] = (Right CharTypeToken, rest) +lex ['B':'o':'o':'l':rest] = (Right BoolTypeToken, rest) +lex [':':':':rest] = (Right DoubleColonToken, rest) +lex ['!':'=':rest] = (Right NotEqualToken, rest) +lex ['<':'=':rest] = (Right LesserEqToken, rest) +lex ['>':'=':rest] = (Right GreaterEqToken, rest) +lex ['=':'=':rest] = (Right EqualsToken, rest) +lex ['&':'&':rest] = (Right AmpersandsToken, rest) +lex ['|':'|':rest] = (Right PipesToken, rest) +lex ['-':'>':rest] = (Right ArrowToken, rest) +lex ['\'':x:'\'':rest] = (Right (CharToken x), rest) +lex ['\'':'\\':x:'\'':rest] = case get x EscapeMap of + Just t = (Right (CharToken t), rest) + _ = (Left ("Unknown escape: \\" +++ toString x), []) +lex [x:rest] +# t = get x SingleCharTokens +| isJust t = (Right (fromJust t), rest) +| isSpace x = lex rest +| isDigit x = let (is, rest`) = span isDigit rest in + (Right (NumberToken [x:is]), rest`) +| isAlpha x = let (is, rest`) = span (\c.isAlphanum c || c == '_') rest in + (Right (IdentToken [x:is]), rest`) +| otherwise = (Left ("Unexpected character: " +++ toString x), [])